CHEF- RESOURCES - macos_firewall Resource

Features of Chef

The following list of Chef's key attributes:

• Chef uses the popular Ruby language to develop domain-specific languages.
   
• The chef makes no assumptions about the current status of a node. It uses its mechanics to ascertain the machine's status at the moment.
   
• Chef is the best technology to deploy and manage the server, software, and cloud storage.

macos_firewall Resource

To activate the firewall on macOS systems, use the resource macos_firewall.

Syntax

The complete syntax for every property that the macos_firewall resource can use is as follows:

macos_firewall 'name' do
  action      Symbol # defaults to : enable if not specified
end

Where:

• The source is macos_firewall.
• The resource block's name is specified by the author.
• Action specifies the actions the Chef Infra Client will perform to put the node in the desired state.

Actions

The actions of the resource macos_firewall are as follows:

:disable

:enable

:nothing

Unless another resource alerts it to do so, this resource block accomplishes nothing. When alerted, this resource block either executes right away or is scheduled to execute at the conclusion of a Chef Infra Client run.

Properties

There are no properties for this resource.

Common Resource Functionality

Every resource shares the following characteristics:

Common Properties

Every resource shares the following characteristics:

compile_time

Ruby Type: true, false | Default Value: false

Control the stage of the node's resource execution. Run while the resource collection is being constructed by setting the value to true (the compile phase). Run when the Chef Infra Client is configuring the node by setting false (the converge phase).
 

ignore_failure

Ruby Type: true, false, :quiet | Default Value: false

If a resource fails for any reason, the recipe will still be executed. Quiet won't show the complete stack trace if a resource fails.
 

retries

Ruby Integer Type | 0 Default Value

The number of times the resource will be tried once any exceptions are caught.
 

Retry_delay

Ruby Type: Integer | Default Value: 2

seconds that pass between retry attempts.
 

Sensitive

Ruby Type: false, true, default: false

Make sure that Chef Infra Client does not record critical resource information.

Notifications

notifies

Ruby Type: Symbol, 'Chef::Resource[String]'
 

When one resource's state changes, it may alert another resource to take appropriate action. Name the resource, specify the activity it should perform, and then set a timer for that action. When notifying multiple resources, use a notifies statement for each resource that needs to be informed.
 

An error is triggered if the referenced resource is missing. In contrast, if the source resource cannot be located, subscribes will not fail.
 

When a notification is run during the course of a Chef Infra Client run is determined by a timer. There are the upcoming timings available:
 

:before

Specifies that the action on a resource that has received a notification should be executed. It should be executed before processing the resource block that contains the notification.
 

:delayed

Default. Specifies that execution of notification should be queued up for execution. At the conclusion of a run of the Chef Infra Client.
 

:immediate,:immediately

Specifies that for each resource informed, a notification should be run right away.

The notifications syntax is:
 

notifies :action, 'resource[name]', :timer

subscribes

Ruby Type: Symbol, 'Chef::Resource[String]'

If the status of the resource being listened to changes, the resource listening to it may take action. Name the resource, describe the action that will be taken, and then set a timer for that action.
 

Be aware that when you use subscribes, the resource you are listening to is not affected by the action you specify. For instance:

file '/etc/nginx/ssl/example.crt' do
  mode '0600'
  owner 'root'
end

service 'nginx' do
  subscribes :reload, 'file[/etc/nginx/ssl/example.crt]', :immediately
end

In this instance, whenever the certificate file for nginx, found at /etc/nginx/ssl/example.crt, is modified. The subscribes property reloads the nginx service. The:reload action is executed for the resource (in this case, nginx) when a change is noticed by subscribes. It makes no modifications to the certificate file itself.
 

There won't be a problem with the subscription if the other resource is nonexistent. In contrast, notifications have stricter semantics and will report an error if the other resource isn't there.
 

When a notification is run during the course of a Chef Infra Client run is determined by a timer. There are the upcoming timings available:
 

:before

Specifies that the action on a resource that has received a notification should be executed. It should be executed before processing the resource block that contains the notification.
 

:delayed

Default. Specifies that the execution of notification should be queued up for execution. At the conclusion of a run of the Chef Infra Client.
 

:immediate,:immediately

Specifies that for each resource informed, a notification should be run right away.
 

The subscribes syntax is as follows:

subscribes :action, 'resource[name]', :timer

Guards

During the execution stage of a Chef Infra Client run, the condition of a node can be assessed using a guard property. A guard property is then used to inform Chef Infra Client whether it should keep running a resource in response to the findings of this assessment. Both a Ruby block value and a string value are acceptable values for a guard property:
 

• A string is used to run a command in the shell. The guard is applied if the command returns 0. The guard property is not used if the command returns any other value. In a PowerShell script, string guards can return true in addition to 0 and launch Windows PowerShell commands.
   
• The Ruby code that executes a block must return either true or false. The guard property is used if the block returns true. The guard attribute is not used if the block returns false.

By allowing a resource to check for the desired state as it is being performed. And then do nothing if the required state is present. A guard property is helpful for guaranteeing that a resource is idempotent.

Properties

A guard that is evaluated during the execution phase of a Chef Infra Client run can be defined using the following properties:

not_if

Prevent the execution of a resource when a condition evaluates to true.

 

only_if

Only permit the use of a resource if the condition returns true.

Examples

The examples below show different methods for utilizing the macos firewall resource in recipes:
 

Turn on the macOS Firewall:
 

macos_firewall 'Enable Firewall Protection' do
  action :enable
end

Turn off the macOS Firewall:

macos_firewall 'Disable Firewall Protection' do
  action :disable
end

Frequently Asked Questions

Explain the major components of Chef.

The major components of the chef are the chef server, chef node, and chef workstation.

What exactly is a Chef Node, and why is it significant?

The node, a component of the Chef design, can be viewed as a physical server or a virtual machine. With Chef, any resource may be used.

What distinguishes a recipe in Chef from a cookbook?

A Recipe is created when resources are combined, and this is helpful for carrying out settings and policy. Combining Recipes creates a Cookbook, which is much easier to maintain than a single Recipe.

Why are SSL certificates used in Chef?

The Chef's initial configuration, as well as the creation of the certificate and private keys in Nginx, require the SSL certificate. This makes sure that between the Chef Client and Chef Server, the appropriate data can be obtained.

Conclusion

In this article, we have extensively discussed CHEF- RESOURCES - macos_firewall Resource.

We hope this blog has helped you enhance your knowledge. If you would like to learn more. Check out our articles on AWS, AWS Certification, and Cloud Computing. Practice makes a man perfect. To practice and improve yourself in the interview. You can check out Top 100 SQL problems, Interview experience, Coding interview questions, and the Ultimate guide path for interviews.